Weather: Now you see it, now you don't - where'd the Sky Tower go?

An aversion layer of cloud hangs low over Auckland's CBD partially obscuring the Sky Tower on an otherwise sunny day. Photo / Peter Meecham

Auckland's most iconic building was M.I.A this morning for many, something one resident described as "bizarre".

Cloud and fog engulfed the Sky Tower this morning, making the city skyline look like it was back in the 1980s before the Auckland icon was built.

Grey Lynn resident Nadia Tolich says she usually has a clear view of the tower and it was quite bizarre to see the entire structure shrouded in cloud.

"If and when, fog or low cloud rolls in, usually the top of the Sky Tower is hidden - not the whole thing."

It looks like a mist or fog is creeping over the CBD, says Tolich.

An aversion layer of cloud hangs low over Auckland's CBD partially obscuring the Sky Tower on an otherwise sunny day. Photo / Peter Meecham

"Meanwhile clear blue sky and sunshine is warming up Grey Lynn. It is certainly a city divided ... by the weather."

So what really happened?

MetService meteorologist Tui McInnes says what's happening is not as dramatic as it looks.

Sea fog that has been sitting in the Hauraki Gulf area has been pushed over the city by northerlies, McInnes says.

"It's just warmer air that is coming from the north that is cooled by either cooler ocean and by cooler land. Over the land, fog breaks really quickly because as the sun comes up it heats the land really, really fast. Water doesn't heat nearly as quickly. If you get fog or cloud over the water, it tends to take a bit longer. This is what's happened in this case, it's been able to pushed in a bit."

An aversion layer of cloud hangs low over Auckland's CBD partially obscuring the Sky Tower on an otherwise sunny day. Photo / Peter Meecham

The reason it's sticking around the Sky Tower is it's continually getting fed in the northerlies, he says.

He says, while the broad situation is quite common, in this case: "It's the right ingredients coming together at the right time."

And for those with reservations at the Sky Tower's The Sugar Club restaurant anticipating sky high views over the city, there's no need to cancel those bookings just yet.

McInnes says the cloud is breaking up now.

"It's taking a wee while to break up and disperse. It is lifting. It will be short-lived."